ISDN: capi, use kref from tty_port

After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.

Here it is enough to switch to refcounting in tty_port.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 17 insertions, 19 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index c679867c2ccd..89562a845f6a 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -77,8 +77,6 @@ struct ackqueue_entry {
 };
 
 struct capiminor {
-        struct kref kref;
-
         unsigned int      minor;
 
         struct capi20_appl      *ap;
@@ -190,7 +188,20 @@ static void capiminor_del_all_ack(struct capiminor *mp)
 
 /* -------- struct capiminor ---------------------------------------- */
 
-static const struct tty_port_operations capiminor_port_ops; /* we have none */
+static void capiminor_destroy(struct tty_port *port)
+{
+        struct capiminor *mp = container_of(port, struct capiminor, port);
+
+        kfree_skb(mp->outskb);
+        skb_queue_purge(&mp->inqueue);
+        skb_queue_purge(&mp->outqueue);
+        capiminor_del_all_ack(mp);
+        kfree(mp);
+}
+
+static const struct tty_port_operations capiminor_port_ops = {
+        .destruct = capiminor_destroy,
+};
 
 static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
 {
@@ -204,8 +215,6 @@ static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
                 return NULL;
         }
 
-        kref_init(&mp->kref);
-
         mp->ap = ap;
         mp->ncci = ncci;
         INIT_LIST_HEAD(&mp->ackqueue);
@@ -247,21 +256,10 @@ err_out2:
         spin_unlock(&capiminors_lock);
 
 err_out1:
-        kfree(mp);
+        tty_port_put(&mp->port);
         return NULL;
 }
 
-static void capiminor_destroy(struct kref *kref)
-{
-        struct capiminor *mp = container_of(kref, struct capiminor, kref);
-
-        kfree_skb(mp->outskb);
-        skb_queue_purge(&mp->inqueue);
-        skb_queue_purge(&mp->outqueue);
-        capiminor_del_all_ack(mp);
-        kfree(mp);
-}
-
 static struct capiminor *capiminor_get(unsigned int minor)
 {
         struct capiminor *mp;
@@ -269,7 +267,7 @@ static struct capiminor *capiminor_get(unsigned int minor)
         spin_lock(&capiminors_lock);
         mp = capiminors[minor];
         if (mp)
-                kref_get(&mp->kref);
+                tty_port_get(&mp->port);
         spin_unlock(&capiminors_lock);
 
         return mp;
@@ -277,7 +275,7 @@ static struct capiminor *capiminor_get(unsigned int minor)
 
 static inline void capiminor_put(struct capiminor *mp)
 {
-        kref_put(&mp->kref, capiminor_destroy);
+        tty_port_put(&mp->port);
 }
 
 static void capiminor_free(struct capiminor *mp)